Piano action



May 26, 1931. c. E. CAMERON, JR

PIANO ACTION Filed Dec. 23, 1929 INVENTOR Y ATTORNEYS &

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Patented May 26, 1931 UNITED STATES PATENT OFFICE CHARLES EWEN CAMERON, JR., OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO LAUTER- HUMANA (30., A CORPORATION OF NEW JERSEY PIANO ACTION Application filed December 23, 1929. Serial No. 415,915.

This invention relates in general to a novel and improved piano action, and particularly to a piano action for so-called grand pianos as distin ished from upright pianos.

One object the invention is to provide a piano action embodying novel and improved features of construction in the mechanism for striking the piano strings by the actuation of the associated keys, whereby great sensitivity of the mechanism and rapid movement thereof may be obtained with ease of operation and resultant clearness' and sharpness of tone.

The term key is intended to designate either the manually actuated keycommonly used in hand played instruments, or to designate any other parts for imparting movements to the hammers, such as the pneumatics used in player pianos. 1

Another object is to provide in a piano action of this character novel and improved means for preventing or restrainingrebound of the hammer after it has once struck the string to ensure that the hammer shall strike the string only once upon each actuation of the key.

Other objects are to provide a piano action which shall be simple and inexpensive in construction, and light in action or requiring a as small amount of power to actuate the hammer into the contact with the string; to provide a novel and improved construction, combination and mounting of a key, hammer and means for connecting them whereby the hammer is certain to properly strike the string upon both light and heavy touch of the player upon the key, and the hammer'is prevented from repeated rebounding against the string under all conditions; to provide such bination of parts whereby the movement or momentum of the key upon the string-striking operation serves to compensate or offset a novel and improved construction and com-.

the recoil, and to obtain other advantages and results as will be brought out by the following description.

Referring to the accompanying drawings in which corresponding and like parts are designated by the same reference characters throughout the several views:

Figure 1. is a side elevation of a piano aotion embodying my invention, showing it mounted'in a frame which is shown partially in section,

Figure 2 is a top plan view of one piano action taken on the line 2-2 of Figure l, and

Figure 3 is an enlarged fragmentary vertical sectional View through the frictional connection of the hammer lifter or jack with the key;

Specifically describing the illustrated em bodiment'of the invention, the reference character A designates a key frame of known construction having the usual balance rail B upon .which are fulcrumed intermediate their ends, the keys C. As shown, each key preferably has a transverse tapered slot 1 which loosely receives a pivot pin 2 secured in the balance rail B, and beneath the outer end of each key is arranged a cushion stop 3 to limit swinging movement of the key in its hammer actuating movement. Beneath the other end of the key is arranged another cushion stop 4 to limit swinging of the key on its return from its hammer actuating movement. The usual key leads 5 are provided to insure the proper weight and balance of the keys.

At the inner end of each of the keys is provided a shock absorber which may consist of a cylindrical socket or recess 6 lined with a shock absorbing substance, for example, re silient rubber? which maybe in the form of a short tube. Preferably this shock absorber also has friction producing characteristics. WVithin this recess is arranged the tapered or conical end 8 of a hammer lifter orjack 9, formed of wood or any other suitable material and which preferably will establish a frictional contact with the friction tube 7 At this point, it should be understood that the shock absorbing material may be placed on theend of the jack 9 instead of in the socket 6, the socket might be tapered 0 instead of the end of the jack, or both the Walls of the socket and the end of the jack might be tapered, and the socket might be formed in the lifter and a tapered projection on the key, all Within the scope of the invention. The jack 9 includes a rod'lO which has a screw threaded and adjustable connectionwith the body 11 for varyingthe length of the litter or jack, and a jam nut 12 preferably formed of frictional material, such as leather, is threaded on the rod to hold the partslO and 11 in adjusted position, The upper end of the rod 10 is hooked at 1'3 and passes through an opening ltinthe shank 15 of a hammer 16, and preferably the opening 14 is lined with a soft filler -1 7,foreX'-. ample, a felt bushing.

A hammer head 18 is mounted'at one end of theshank 15:and the other end oi the shank I is pivoted at 19 in a block 20 secured, as by screws 21, to a hammer supporting rail 22 so that the hammer may oscillate ina'verti'cal plane toward and from a string D. The relative sizes of the parts and their interconnections are such that upon full movement' of the key pivotally upon the pin 2 through its hainmer'actuati-ng operatiom the hammer is moved tea point slightly spaced from the string, asshown by dot and: dash lines E. It will be noted that'the "distance between'the points of Contact ofthe hammer lifter or jack 9 with the key and the hammer, is lessthan-that required tocause the hammer to contact with the string D atthe end of the norm-a1'string striking movement of the key,so that the hammer could not strike the string w-itheutthe relative movement between the jack 9 and the key which is permitted by the taperedendB- of the jack in the'recesstii However, the power and momentum caused by the actuation of the key is imparted to the hammer so that when the key strikes the stop 3, the lifter 9 may move'rela'tively to the key so that the hammeris thrown against the string under influence of this power and momentum. Thisappears to be particularly efiective for playing with light'touch upon the key. The hammer rec'oils from thestring as the key returns tothe stop tfuponrelea'se o'fpressure by the player, andtheshockol' "the recoi'li'sabsorhed by the rubber 7 which does not 'have'sufiicient reaction on the lifter to cause the key to rebound against the string.

Also the frictional contactbetWeen't'he rub her and the tapered end 8 of the lifter appears to in part restrain rebound of'the hammer, so that the hammer is prevented or restrained from repeated striking oflthe string upon a single actuation of the key. When greater pressure is applied to the key by'the playerand the keystrikes the stop"3,t-he other end of the key apparently rises upon the pin 2 sothat the momentumand power therein in part compensate-or ofl'set theenergy in the hammer uponits recoil from the string, which in connection with the shock absorber or cushion 7 effectually prevents rebound of the hammer against the string. Therefore, it will be observed, that the combination and connection and the sensitiveness of the parts are such that the hammer can be caused to strike the stringrepeatedly as often and as rapidly as desired by the player, under either light or heavy touch upon the key, butregardless of the rapidity or force in the "action ofthe keysgthe' hammer can strike the string only once for each actuation of the key. Clear tones are thus insured,

A damper construction is combined With the key action soas to normally damp the strings, and undamp them or move therdamper i rom contact therewith :as the hammer is actuated into-contact with the string. This -When the key is-actuated to throw the ham- 1 mer against 'tl'iestring, the damper crank is raised and correspondingly raises thedamp er :head from'the string just prior. to the striking'of the st-ring' by the hammer. VV-hen the hammer rebounds fromthe string, upon rele'aseof the'key, the damper immediately falls'fby gravity upon the string so as to damp V vibration thereof.

' It will he observed that the piano action embodying my invention is extremely simple, embodying a small number of simple parts and a minimum number of connections hetweenthe parts. The action is thus light in Weight and requires-a small amount of power foroperation. At the same time it is extreme 1y. sensitive permits rapid successive.

striking of the St ng by the hammers, as

in executingatre'mo1'o,iwith theimpor'tant advantage of the invention that the-hammer is prevented from repeated rebounding upon the string, and by extremely'simple means which is incomparable with the usual mechanism forthis purpose utilized in piano actions. This same means, the resilient "tube 7 andthe tapered end; 8 of the lift-er, also serve as a stop to limit recoilo'f the hammer from the string, thereby 'o'bvi atin'gth'e neces= 1 sity for a stop railfor the l-ra'mmer's.

While I, have shown and described one specific embodiment fof -my "invention, it should be understood that this is primaiily' for the purpose ofillustrating the principles ofthe invention, andthat the invention'may be embodied in many different 'cletai'ls of construction without departing from the spirit or scope of the invention.

Having thus described my invention, what I claim is:

1. In a piano, the combination with a string, of a hammer, a key, a single hammer litter between said key and said hammer connected for relative movement with one thereof, the distance between the points of engagement of said litter with said hammer and. said key being less than that required to cause the hammer to contact with said string at the end of the string-striking movement of said key without said relative movement so that upon the string-striking movement of said key movement of said litter will allow said hammer to be thrown against said string by the energy imparted thereto by actuation of said key and permit said hammer to recoil idly independent of said key, and shock-absorbing means both to limit recoil of the hammer and to restrain rebound of the hammer to the string.

2. In a piano, the combination with a string, of a key, a hammer, a single lifter connected at one end to said hammer, and a shock-absorbing connection between the other end of said litter and said key to absorb the shock of the recoil of the hammer from said string.

3. In a piano, the combination with a string, of a hammer, a key, a litter interposed between said key and said hammer for actuating the latter to strike said string, said litter being connected to said key for relative movement and connected to said hammer to move therewith, the distance between the points of engagement of said lifter with said hammer and said key being less than that required to cause the hammer to contact with said string at the end of the string-striking movement of said key without said relative movement, so that upon string-striking movement of. said hammer said lifter will move relatively to said key and said hammer will be thrown against said string by the energy imparted to it by actuation of said key and said hammer will recoil idly inde' pendent of said key, and shock-absorbing means to limit recoil of the hammer and restrain rebound of the hammer to the string.

a. In a piano, the combination with a string, of a hammer, a key having a recess, and a litter interposed between said key and said hammer for actuating the latter to strike said string, said lifter having a portion to fit into and to contact with and move relatively to the walls of said recess and being connected to said hammer to move therewith, said walls of? said recess having shock-absorbing qualities, the distance between the points of engagement of said litter with said hammer and the walls of said recess being less than that required to permit said hammer to contact with the string at the end of the string-striking movement of said key without said relative movement between said lifterand said recess, so that upon stringstriking movement of said hammer said lifter will move relatively to said key to cause the hammer to be thrown against said. string by the energy imparted to it by actuation of said key,,and shock of the recoil of said hammer will be absorbed by the walls of said recess, whereby rebound of the hammer to the string is restrained.

5. In a piano, the combination with a string, of a hammer, a key having a cylindrical recess provided on its walls with shockabsorbing and friction-producing material, and a litter interposed between said key and said hammer for actuating the latter to strike said string, said lifter having a tapered portion to fit into and frictionally engage the walls of said recess to move relatively thereto and being connected to said hammer to move therewith, the distance between the points of engagement of said lifter with said hammer and the walls of said recess being less than that required to permit said hammer to contact with the string at the end of the stringstriking movement of said key without said relative movement between said lifter and the walls of said recess, so that upon string-striking movement of said hammer saidlifter will move relatively to said key to cause said hammer to be thrown against said string by the energy imparted to it by actuation of said key, and said shock-absorbing material upon recoil of said hammer from the strings will prevent rebound of the hammer to the string. 7 6. In a piano, the combination with a string, of a hammer pivotally mounted at one end, a key pivotally mounted intermediate its ends, stops at each end to limit pivotal movement, said pivotal mounting being such as to permit bodily movement of the key on said mounting toward said string when pivotal movement is stopped, a lifter pivotally connected at one end to said hammer and connected to one end of said key for movement relative thereto, the distance between the points of engagement of said lifter with said key and said hammer being less than required to permit said key to contact with the string at the end of the string-striking movement of said key without such relative movement between said key and said litter, so that upon swinging of said key in one direction said lifter will move relatively to said key to cause the hammer to be actuated to strike said string under the energy imparted to it by said actuation of the key, and a shock-absorber against which said hammer can recoil to restrain rebound of the hammer.

7. In piano, the combination with a string, of a hammer pivotally mounted at one end, a key pivotally mounted intermediate its ends, stops at each end of said key to limit pivotal movement, said pivotal mounting be ing such as to permit bodily movement of the key on said mounting toward saidstring when pivotal movement is stopped, and a lifter pivotally connected at one end to said hammer, means connecting the other end of said lifter to one end of saidkey for relative movement including -a1shock-absorber, the distance between the points of engagement of said litter V with said key andsaid hammer being less than 1' required to permit said key to "contact with the string at the end of the string-striking movement of said key without said relative movement between said key andsaid lifter, so that upon swinging of said key in one direc-, 15 tion said lifter willmove relatively-to said key to cause said hammer to be actuated to strike saidstring under the energy imparted to it by actuation of said key, and the shock of the recoilof said hammer will be absorbed 29 by said shock-absorber to restrain rebound of the hammer. 7 a

S. In a piano, the combination with a string, of a hammer pivotally mounted at one end, a key pivotally mounted intermediate is 25 its ends, stops at each end of the key to limit 1 pivotal movement,said pivotal mountingbeing suchastopormit bodily movement of the key on saidmounting towardrsaid string when pivotal movement is stopped, one end of said so key having a recess provided with shock-absorbing walls, a litter connected at one end .to saidhammer and having its other end tapered and fitted intosaid recess to move into and out thereof, the distance between thepoints 35 of engagement of said lifter with said key and said hammer being less than required to permit saidkey to contact with the string at the end of the string-striking movement of said key without relative movement between as said key andsaid lifter, so that upon swing ing of said key in one direction said lifter will move relatively to said key to causesaid hammer to beactuated tojstrike said string,

. and the shock of the recoil of the hammer will I 5 be absorbed by said Walls of said recess.

9. The piano set forth inclaim 8, wherein said'taperedend ofthe lifter has a releasable frictional engagement with'said walls of the recess. 1

CHARLES EWEN CAMERON, JR; 

